neural and hormonal explanation- a01 Flashcards
Role of the hypothalamus
Integrates nervous and endocrine systems, maintains the homeostasis of blood glucose levels.
what is the lateral hypothalamus (LH)
Feeding center (‘on switch’) activated when glucose levels fall below threshold, triggering hunger and eating behaviors.
what is the ventro-medial hypothalamus (VMH)
Satiety centre (‘off switch’), activated when glucose levels rise above threshold, making individual feel full and stop eating.
what is the role of ghrelin
Appetite stimulant – more ghrelin is released by the stomach the longer we go without food.
what is the role of leptin
Appetite suppressant produced by fat cells – when levels rise above threshold VMH responds.
what is our main source of energy
glucose (sugar)
what is homeostasis
organism maintaining a steady environment
what are 2 strengths
real world application
wide range of empirical and consistent findings to support
who researched the first point
Heymsfield
what did he find
conducted a rigorous longitudinal study which found that administering leptin to participants led to sustained weight loss over time, especially in obese individuals with leptin deficiencies.
whys this good
robust empirical support for the theory that leptin acts as an appetite suppressant. The clear link between increased leptin and reduced food intake adds scientific validity to the theory
Demonstrate the practical value of the theory, as it not only explains behavior but also informs effective medical interventions, increasing both its external validity and usefulness.
what 2 researchers back that it has empirical and consistent research
Hetherington + Ranson
Cummings
what did the first people do
lesioned VMH of rats which caused them to become hyperphagic (overeat)
what happened to them
become severely obese as they had a damaged satiety centre. (evidence for DUAL CENTRE MODEL)
what did the second person find
found ghrelin levels directly reflect stomach emptiness and are closely related to feelings of hunger.
whys this useful
The consistency and empirical support across various studies and samples demonstrate the validity and reliability of the Dual Centre Model. This solid research foundation makes it a powerful explanation for eating behavior.
what’s a weakness
biologically reductionist
role of homeostasis and hypothalamus undermined by contradictory evidence
who provided evidence to support this
Woods et al.
what did he find
argued that glucose-monitoring mechanisms only activate in extreme energy deficits. In everyday situations, factors like social norms, meal timing, and cultural traditions often override homeostatic signals, indicating that eating behaviour is not solely biologically driven.
what can we conclude from this
reduces eating behaviour to a purely physiological process, neglecting the complex interplay of psychological, social, and environmental influences. The failure to account for these factors weakens the theory’s ability to explain eating behaviour in the real world.
incomplete and limits explanatory power. Other models must be considered to offer a more holistic understanding of eating behaviour.
